1. Field of the Invention
The present invention relates generally to the field of conditioning and cleaning fiber optic connectors, and more particularly to a process for cleaning connectors that is field deployable and provides similar performance to mechanical or laser conditioning processes.
2. Description of Related Art
Fiber-optic waveguides are an attractive transmission medium for modern telecommunication networks because of the high bandwidth associated with light transmission. Moreover, optical fibers provide high bandwidth with relatively low loss or attenuation characteristics when compared with metallic media. However, practical considerations dictate that most networks be comprised of many individual sections of optical cable joined together through a connector or fusion spliced with an electric arc. While splicing offers the highest performance transmission characteristics, remateable connectors are generally preferred to splicing when flexibility is needed for reconfiguration of the network as the network topology changes. To maintain the high quality signal transmission characteristics of the optical fiber, the connectors must be designed and conditioned to minimize optical loss and signal reflectance. For high performance applications, such as analog video, reflectance values of -60 dB or less are desired to ensure that the transmitted signal is not unduly distorted.
Traditional methods for conditioning fiber ends and connectors include flame polishing, grinding and/or polishing using a mechanical device or machine often in conjunction with an aqueous slurry, and treatment of the fiber ends via exposure to a laser beam, electric arc or a microtorch. Once the end faces of the connector are altered to produce the desired performance, it is customary to clean the connector end faces whenever cable segments are first joined or whenever they are remated to remove impurities that can buildup over time. These impurities degrade the performance of the connector by causing unwanted signal reflectance.
Heretofore, connector cleaning processes have used solvents containing volatile organic compounds (VOCs), such as alcohol, to restore performance levels. Unfortunately, these cleaning processes have been unable to improve connector reflectance beyond the range of -50 dB to -55 dB. Inasmuch as organic solvents are known to be effective at removing organic impurities and oils, other factors are clearly dominant when trying to achieve reflectance values beyond -55 dB.
While the aforementioned techniques of polishing or mechanically cleaning the connector and the fiber are effective in restoring connector performance to -55 dB and below, it is readily apparent that these techniques do not lend themselves to application in a field setting. Thus, what is needed is a field deployable cleaning process for optical connectors that exceeds the -55 dB performance level achievable by existing cleaning processes without resorting to intrusive mechanical remedies.
While cleanliness of the cable connections is a critical factor in maintaining the performance of a fiber-optic network, any cleaning process used is a procedure that produces waste. Moreover, U. S. manufacturers are subject to strict federal, state and local legislation that regulate water discharges and treatment and disposal of hazardous chemicals. As discussed in the foregoing, many solutions used to clean fiber-optic connectors contain VOC based solvents and/or phosphate based detergents that are known to adversely affect the human respiratory tract, skin, eyes, liver, kidneys, cardiovascular system, nervous system, and cause an increased risk for developing cancer. Notwithstanding the impact these solvents and detergents have on the public health and welfare, manufacturers may also incur economic hardships through imposition of fines, penalties or fees from governmental environment protection agencies. Thus, it is therefore desirable that a new connector cleaning process be developed that is effective at removing organic based impurities and oils but uses environmentally safe solvents and detergents.
In view of the foregoing discussion, what is sought after is a fiber-optic connector cleaning process that can achieve optical reflectance levels of -55 dB or less while eliminating or dramatically reducing the use of regulated or hazardous chemicals and compounds.